Solid-state image sensor

ABSTRACT

A solid-state image sensor is provided. The solid-state image sensor includes photoelectric conversion elements and a color filter layer disposed above the photoelectric conversion elements. The photoelectric conversion elements and the color filter layer form normal pixels and auto-focus pixels, the color filter layer that correspond to the normal pixels are divided into first color filter segments and second color filter segments, the first color filter segments are disposed on at least one side that is closer to an incident light, and the width of the first color filter segments is greater than the width of the second color filter segments.

BACKGROUND Technical Field

The embodiments of the present disclosure relate to image sensors, andin particular they relate to solid-state image sensors that includecolor filter segments having variable widths.

Description of the Related Art

Solid-state image sensors (e.g., complementary metal-oxide semiconductor(CMOS) image sensors) have been widely used in various image-capturingapparatuses such as digital still-image cameras, digital video cameras,and the like. Signal electric charges may be generated according to theamount of light received in the light-sensing portion (e.g.,photoelectric conversion element) of the solid-state image sensor. Inaddition, the signal electric charges generated in the light-sensingportion may be transmitted and amplified, whereby an image signal isobtained.

Recently, the trend has been for the pixel size of image sensorstypified by CMOS image sensors to be reduced for the purpose ofincreasing the number of pixels to provide high-resolution images. Whenan oblique incident light (e.g., chief ray angle (CRA) is not equal to0) directly radiates into the solid-state image sensor that includesdifferent normal pixels (e.g., different color filter segments) andphase-detection auto-focus (PDAF) pixels, different sensitivities of thepixels may occur according to different positions, resulting in channelseparation. This channel separation will cause problems with imagedetection.

BRIEF SUMMARY

According to some embodiments of the present disclosure, the solid-stateimage sensor includes color filter segments having variable widths,which may improve channel separation, thereby improving the quality ofthe image signal from the photoelectric conversion elements of thesolid-state image sensors.

In accordance with some embodiments of the present disclosure, asolid-state image sensor is provided. The solid-state image sensorincludes photoelectric conversion elements and a color filter layerdisposed above the photoelectric conversion elements. The photoelectricconversion elements and the color filter layer form normal pixels andauto-focus pixels, the color filter layer that correspond to the normalpixels are divided into first color filter segments and second colorfilter segments, the first color filter segments are disposed on atleast one side that is closer to an incident light, and the width of thefirst color filter segments is greater than the width of the secondcolor filter segments.

In some embodiments, at least one of the first color filter segmentsthat is adjacent to the auto-focus pixels has a greater width than otherfirst color filter segments.

In some embodiments, the color filter layer has four color regionscorresponding to at least two different colors, and at least one of theauto-focus pixels is disposed in and corresponds to one of the fourcolor regions.

In some embodiments, the width of the first color filter segments in oneof the four color regions is different from the width of the first colorfilter segments in another of the four color regions.

In some embodiments, each color region corresponds to an n² pixel array,where n is an integer greater than or equal to 3.

In some embodiments, the auto-focus pixels form an auto-focus pixelarray, and the auto-focus pixel array is a p×q pixel array, where p andq are integers less than n.

In some embodiments, the four color regions form a unit pattern, andmore than one unit pattern form an array.

In some embodiments, the auto-focus pixels are disposed in andcorrespond to all of the four color regions.

In some embodiments, the auto-focus pixels are disposed in andcorrespond to at least two of the four color regions.

In some embodiments, the normal pixels have a constant pixel width thatis equal to or less than 0.7 μm.

In some embodiments, the solid-state image sensor further includes agrid structure disposed between the first color filter segments andbetween the second color filter segments. The grid structure has gridsegments, and each grid segment has a variable width.

In some embodiments, the solid-state image sensor further includes ametal grid disposed on the bottom of the grid structure. The metal gridhas metal segments, and the metal segments have a constant width.

In some embodiments, each metal segment has a variable width withrespect to the corresponding grid segment.

In some embodiments, the solid-state image sensor further includescondensing structures disposed on and corresponding to the first colorfilter segments and the second color filter segments.

In some embodiments, each condensing structure has a variable width withrespect to the corresponding one of the first color filter segments andthe second color filter segments.

In some embodiments, at least one of the first color filter segments andthe second color filter segments has a shift with respect to thecorresponding photoelectric conversion elements.

In some embodiments, the auto-focus pixels form two or more auto-focuspixel arrays.

In some embodiments, the auto-focus pixel arrays are disposed in andcorrespond to at least two of the four color regions.

In some embodiments, the auto-focus pixel arrays are disposed in andcorrespond to all of the four color regions.

In some embodiments, the normal pixels include red color filters, greencolor filters, blue color filters, yellow color filters, white colorfilters, cyan color filters, magenta color filters, or IR/NIR colorfilters.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be more fully understood from the following detaileddescription when read with the accompanying figures. It is worth notingthat, in accordance with standard practice in the industry, variousfeatures are not drawn to scale. In fact, the dimensions of the variousfeatures may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 is a partial top view illustrating the solid-state image sensorin accordance with some embodiments of the present disclosure.

FIG. 2 is a partial cross-sectional view illustrating the solid-stateimage sensor along line A-A′ in FIG. 1 .

FIG. 3 is a partial cross-sectional view illustrating the solid-stateimage sensor in accordance with some other embodiments of the presentdisclosure.

FIG. 4 is a partial cross-sectional view illustrating the solid-stateimage sensor in accordance with some other embodiments of the presentdisclosure.

FIG. 5 is a partial cross-sectional view illustrating the solid-stateimage sensor in accordance with some other embodiments of the presentdisclosure.

FIG. 6 is a partial top view illustrating the solid-state image sensorin accordance with some embodiments of the present disclosure.

FIG. 7 is a partial cross-sectional view illustrating the solid-stateimage sensor along line B-B′ in FIG. 6 .

FIG. 8 is a partial top view illustrating the solid-state image sensorin accordance with some other embodiments of the present disclosure.

FIG. 9 is a partial top view illustrating the solid-state image sensorin accordance with some embodiments of the present disclosure.

FIG. 10 is a partial top view illustrating the solid-state image sensorin accordance with some embodiments of the present disclosure.

FIG. 11 is a partial top view illustrating the solid-state image sensorin accordance with some embodiments of the present disclosure.

FIG. 12 is a partial top view illustrating the solid-state image sensorin accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the subject matterprovided. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, a firstfeature is formed on a second feature in the description that followsmay include embodiments in which the first feature and second featureare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first feature and secondfeature, so that the first feature and second feature may not be indirect contact.

Furthermore, spatially relative terms, such as “beneath,” “below,”“lower,” “on,” “above,” “upper” and the like, may be used herein forease of description to describe one element or feature's relationship toother elements or features as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

In the present disclosure, the terms “about,” “approximately” and“substantially” typically mean +/−20% of the stated value, moretypically +/−10% of the stated value, more typically +/−5% of the statedvalue, more typically +/−3% of the stated value, more typically +/−2% ofthe stated value, more typically +/−1% of the stated value and even moretypically +/−0.5% of the stated value. The stated value of the presentdisclosure is an approximate value. That is, when there is no specificdescription of the terms “about,” “approximately” and “substantially”,the stated value includes the meaning of “about,” “approximately” or“substantially”.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It shouldbe understood that terms such as those defined in commonly useddictionaries should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined in the embodiments of the present disclosure.

The present disclosure may repeat reference numerals and/or letters infollowing embodiments. This repetition is for the purpose of simplicityand clarity and does not in itself dictate a relationship between thevarious embodiments and/or configurations discussed.

Solid-state image sensors may be roughly classified into two groups interms of the direction of light incident on a light receiving unit. Oneis the front-side illuminated (FSI) image sensors that receive lightincident on the front side of a semiconductor substrate on which thewiring layer of the reading circuit is formed. Another is the back-sideilluminated (BSI) image sensors that receive light incident on the backside of a semiconductor substrate on which no wiring layer is formed.For imaging a color image, color filter layers may be provided in theFSI and BSI image sensors.

FIG. 1 is a partial top view illustrating the solid-state image sensor100 in accordance with some embodiments of the present disclosure. FIG.2 is a partial cross-sectional view illustrating the solid-state imagesensor 100 along line A-A′ in FIG. 1 . In more detail, FIG. 1 shows thepixel arrangement of the solid-state image sensor 100, and FIG. 2 showsa portion of the cross-sectional view of the solid-state image sensor100. It should be noted that some components of the solid-state imagesensor 100 have been omitted in FIG. 1 and FIG. 2 for sake of brevity.

Referring to FIG. 1 , in some embodiments, the solid-state image sensor100 includes normal pixels (e.g., Gr1, Gr2, Gr3, Gr4, Gr5, Gr6, Gr7,Gr8, R1, R2, R4, R5, R6, R7, R8, R9, B1, B2, B3, B4, B5, B6, B8, B9,Gb2, Gb3, Gb4, Gb5, Gb6, Gb7, Gb8, and Gb9) and auto-focus pixels, andthe auto-focus pixels form an auto-focus pixel array PDAF. In someembodiments, the normal pixels have a constant pixel width that is equalto or less than 0.7 μm.

Referring to FIG. 2 , in some embodiments, the solid-state image sensor100 includes a semiconductor substrate 101 which may be, for example, awafer or a chip. The semiconductor substrate 101 has a front surface101F and a back surface 101B opposite to the front surface 101F. In someembodiments, multiple photoelectric conversion elements 103 (e.g.,photodiodes) are formed in the semiconductor substrate 101. For example,the photoelectric conversion elements 103 in the semiconductor substrate101 may be isolated from each other by isolation structures (not shown)such as shallow trench isolation (STI) regions or deep trench isolation(DTI) regions. The isolation structures may be formed in thesemiconductor substrate 101 using etching process to form trenches andfilling the trenches with an insulating or dielectric material.

As shown in FIG. 2 , the photoelectric conversion elements 103 may beformed on the back surface 101B of the semiconductor substrate 101, anda wiring layer 105 may be formed on the front surface 101F of thesemiconductor substrate 101, but the present disclosure is not limitedthereto. The wiring layer 105 may be an interconnect structure thatincludes multiple conductive lines and vias embedded in multipledielectric layers, and may further include various electric circuitsrequired for the solid-state image sensor 100. Incident lights mayradiate onto the side of the back surface 101B and be received by thephotoelectric conversion elements 103.

In the embodiment shown in FIG. 2 , the solid-state image sensor 100 isreferred to as a back-side illuminated (BSI) image sensor. In some otherexamples, the solid-state image sensor may be a front-side illuminated(FSI) image sensor. The semiconductor substrate 101 and the wiring layer105 shown in FIG. 2 may be inverted for FSI image sensor. In the FSIimage sensor, incident lights radiate onto the side of the front surface101F, pass through the wiring layer 105 and then are received by thephotoelectric conversion elements 103 formed on the back surface 101B ofthe semiconductor substrate 101.

As shown in FIG. 2 , the solid-state image sensor 100 may also include ahigh dielectric-constant (high-κ) film 107 formed on the back surface101B of the semiconductor substrate 101 and covering the photoelectricconversion elements 103. The high-κ film 107 may include hafnium oxide(HfO₂), hafnium tantalum oxide (HMO), hafnium titanium oxide (HMO),hafnium zirconium oxide (HfZrO), tantalum pentoxide (Ta₂O₅), any othersuitable high-κ dielectric material, or a combination thereof, but thepresent disclosure is not limited thereto. The high-κ film 107 may beformed by a deposition process. The deposition process is, for example,chemical vapor deposition (CVD), plasma enhanced chemical vapordeposition (PECVD), atomic layer deposition (ALD), or another depositiontechnique. The high-κ film 107 may have a high-refractive index and alight-absorbing ability.

As shown in FIG. 2 , the solid-state image sensor 100 may furtherinclude a buffer layer 109 formed on the high-κ film 107. The bufferlayer 109 may include silicon oxides, silicon nitrides, siliconoxynitrides, any other suitable insulating material, or a combinationthereof, but the present disclosure is not limited thereto. The bufferlayer 109 may be formed by a deposition process. The deposition processis, for example, spin-on coating, chemical vapor deposition, flowablechemical vapor deposition (FCVD), plasma enhanced chemical vapordeposition, physical vapor deposition (PVD), or another depositiontechnique.

As shown in FIG. 2 , in some embodiments, the solid-state image sensor100 includes a color filter layer 115 disposed above the photoelectricconversion elements 103, and the color filter layer 115 has (or isdivided into) color filter segments. For example, the green color filterlayer 115G is disposed above the photoelectric conversion elements 103,and the green color filter layer 115G has (or is divided into) greencolor filter segments 115GS as shown in FIG. 2 .

Referring to FIG. 1 and FIG. 2 , in some embodiments, the photoelectricconversion elements 103 and the color filter layer 115 (or color filtersegments) form the normal pixels (e.g., Gr1, Gr2, Gr3, Gr4, Gr5, Gr6,Gr7, Gr8, R1, R2, R4, R5, R6, R7, R8, R9, B1, B2, B3, B4, B5, B6, B8,B9, Gb2, Gb3, Gb4, Gb5, Gb6, Gb7, Gb8, and Gb9) and the auto-focuspixels, the color filter layer 115 that correspond to the normal pixelsare divided into first color filter segments (e.g., Gb8 in FIG. 1 andFIG. 2 ) and second color filter segments (e.g., Gb2/Gb5 in FIG. 1 andFIG. 2 ), the first color filter segments are disposed on at least oneside that is closer to the incident light L, the second color filtersegments are disposed on other positions, and the width of the firstcolor filter segments is greater than the width of the second colorfilter segments.

As shown in FIG. 1 , in some embodiments, the color filter layer 115 hasfour color regions CR1, CR2, CR3, and CR4, and at least one of theauto-focus pixels is disposed in and corresponds to one of the fourcolor regions CR1, CR2, CR3, and CR4. In some embodiments, each of thecolor regions CR1, CR2, CR3, and CR4 corresponds to an n² pixel array,where n is an integer greater than or equal to 3. In some embodiments,the auto-focus pixel array PDAF is a p×q pixel array, where p and q areintegers less than n. For example, each of the color regions CR1, CR2,CR3, and CR4 corresponds to a 3×3 pixel array as shown in FIG. 1 , butthe present disclosure is not limited thereto.

As shown in FIG. 1 , in some embodiments, the four color regions CR1,CR2, CR3, and CR4 form a unit pattern U1. Further, the normal pixelsGr1, Gr2, Gr3, Gr4, Gr5, Gr6, Gr7, Gr8 are in the color region CR1, thenormal pixels R1, R2, R4, R5, R6, R7, R8, R9 are in the color regionCR2, the normal pixels B1, B2, B3, B4, B5, B6, B8, B9 are in the colorregion CR3, and the normal pixels Gb2, Gb3, Gb4, Gb5, Gb6, Gb7, Gb8, Gb9are in the color region CR4. Furthermore, the auto-focus pixel arrayPDAF is in the center of the unit pattern U1. For example, theauto-focus pixel array PDAF is a 2×2 pixel array disposed in the centerof the unit pattern U1 as shown in FIG. 1 , but the present disclosureis not limited thereto.

In some embodiments, the color regions CR1, CR2, CR3, and CR4 correspondto at least two different colors. For example, as shown in FIG. 1 , thecolor region CR1 may correspond to the color green, the color region CR2may correspond to the color red, the color region CR3 may correspond tothe color blue, and the color region CR4 may correspond to the colorgreen, but the present disclosure is not limited thereto.

That is, in some embodiments, the normal pixels include red colorfilters, so that the normal pixels R1, R2, R4, R5, R6, R7, R8, R9receive red light; the normal pixels also include green color filters,so that the normal pixels Gr1, Gr2, Gr3, Gr4, Gr5, Gr6, Gr7, Gr8, Gb2,Gb3, Gb4, Gb5, Gb6, Gb7, Gb8, Gb9 receive green light; the normal pixelsfurther include blue color filters, so that the normal pixels B1, B2,B3, B4, B5, B6, B8, B9 receive blue light. In some other embodiments,the normal pixels include yellow color filters, white color filters,cyan color filters, magenta color filters, IR/NIR color filters, or acombination thereof.

As shown in FIG. 1 and FIG. 2 , the incident light L is from the rightside of the unit pattern U1 of the solid-state image sensor 100, and inthe color region CR4, the color filter layer 115 (the green color filtersegment 115GS) that corresponds to the normal pixel Gb8 is disposed onthe side that is closer to the incident light L, so that the colorfilter layer 115 (the green color filter segment 115GS) that correspondsto the normal pixel Gb8 may be referred to as the first color filtersegment, and the color filter layer 115 (the green color filter segment115GS) that corresponds to the normal pixel Gb5 or the normal pixel Gb2may be referred to as the second color filter segment. In thisembodiments, the width CD8 of the green color filter segment 115GS thatcorresponds to the normal pixel Gb8 is greater than the width CD5 (orCD2) of the green color filter segment 115GS that corresponds to thenormal pixel Gb5 (or Gb2).

Moreover, the width of the green color filter segment 115GS thatcorresponds to the normal pixel Gb7 or Gb9 (which may also be referredto as the first color filter segment) is greater than the width of thegreen color filter segment 115GS that corresponds to the normal pixelGb3, Gb4, or Gb6 (which may also be referred to as the second colorsecond segment).

Similarly, as shown in FIG. 1 , the width of the green color filtersegment 115GS that corresponds to the normal pixel Gr6, Gr7, or Gr8(which may be referred to as the first color filter segment) is greaterthan the width of the color filter segment 115GS that corresponds to thenormal pixel Gr1, Gr2, Gr3, Gr4, or Gr5 (which may be referred to as thesecond color filter segment).

In some embodiments, at least one first color filter segment that isadjacent to the auto-focus pixel array PDAF has a greater width thanother first color filter segments. For example, as shown in FIG. 1 , thenormal pixel Gr6 or Gr8 is adjacent to the auto-focus pixel array PDAF,so that the green color filter segment 115GS that corresponds to thenormal pixel Gr6 or Gr8 may have a greater width than the green colorfilter segment 115GS that corresponds to the normal pixel Gr7, but thepresent disclosure is not limited thereto. In some other embodiments,the green color filter segments 115GS that correspond to the normalpixel Gr6, Gr7, and Gr8 may have the same width.

In some embodiments, the width of the first color filter segment in onecolor region is different from the width of the first color filtersegment in another color region. For example, the width of the greencolor filter segment 115GS that corresponds to the normal pixel Gr6,Gr7, or Gr8 (which may be referred to as the first color filter segment)in the color region CR1 may be different from the width CD8 of the greencolor filter segment 115GS that corresponds to the normal pixel Gb8 inthe color region CR4, but the present disclosure is not limited thereto.

As shown in FIG. 1 and FIG. 2 , in some embodiments, the solid-stateimage sensor 100 includes a grid structure 121 disposed between thecolor filter segments (e.g., the green color filter segments 115GS inFIG. 2 ). As shown in FIG. 2 , in some embodiments, the grid structure121 has (or is divided into) grid segments 121S (or 121S1 or 121S2). Forexample, the grid structure 121 may include a transparent dielectricmaterial that has a low refractive index in a range from about 1.0 toabout 1.99. Moreover, in the embodiments of the present disclosure, therefractive index of the grid structure 121 is lower than the refractiveindex of the color filter layer (e.g., the green color filter layer 115Gin FIG. 2 ).

In some embodiments, each grid segment has a variable width. Forexample, as shown in FIG. 2 , the width LW1 of the grid segment 121S1 isgreater than the width LW2 of the grid segment 121S2, but the presentdisclosure is not limited thereto. The width of the grid segment may beadjusted according to the adjacent (surrounding) color filter segment(e.g., the green color filter segments 115GS in FIG. 2 ).

As shown in FIG. 2 , in some embodiments, the solid-state image sensor100 includes a metal grid 111 disposed on the bottom of the gridstructure 121. For example, the metal structure 111 may include tungsten(W), aluminum (Al), metal nitride (e.g., titanium nitride (TiN)), anyother applicable material, or a combination thereof, but the presentdisclosure is not limited thereto. As shown in FIG. 2 , in thecross-sectional view of the solid-state image sensor 100, the metal grid111 has (or is divided into) metal segments. In the embodiments shown inFIG. 2 , the metal segments have a constant width.

As shown in FIG. 2 , in some embodiments, the solid-state image sensor100 includes condensing structures 119 disposed on and corresponding tothe color filter segments (e.g., the green color filter segments 115GSin FIG. 2 ) for condensing incident light. For example, the condensingstructures 119 may include glass, epoxy resin, silicone resin,polyurethane, any other applicable material, or a combination thereof,but the present disclosure is not limited thereto.

In some embodiments, the condensing structure 119 is a micro-lensstructure, such as a semi-convex lens or a convex lens. In some otherembodiments, the condensing structure 119 is a micro-pyramid structure(e.g., circular cone, quadrangular pyramid, and so on), or amicro-trapezoidal structure (e.g., flat top cone, truncated squarepyramid, and so on). Alternatively, in some embodiments, the condensingstructure 119 is a gradient-index structure.

As shown in FIG. 2 , each condensing structure 119 corresponds to onegreen color filter segment 115GS, but the present disclosure is notlimited thereto. In some other embodiments, each condensing structure119 corresponds to at least two color filter segments.

FIG. 3 is a partial cross-sectional view illustrating the solid-stateimage sensor 100 in accordance with some other embodiments of thepresent disclosure. For example, FIG. 3 may also be a partialcross-sectional view illustrating the solid-state image sensor 100 alongline A-A′ in FIG. 1 .

In some embodiments, at least one color filter segment (the first colorfilter segment and/or the second color filter segment) has a shift withrespect to the corresponding photoelectric conversion element 103. Forexample, as shown in FIG. 1 and FIG. 3 , the green color filter segment115GS that corresponds to the normal pixel Gb5 has a shift s5 withrespect to the corresponding photoelectric conversion element 103. Thatis, the distance between the central axis C5 of the green color filtersegment 115GS that corresponds to the normal pixel Gb5 and the centralaxis P5 of the corresponding photoelectric conversion element 103 is theshift s5. Moreover, as shown in FIG. 1 and FIG. 3 , the green colorfilter segment 115GS that corresponds to the normal pixel Gb2 has ashift s2 with respect to the corresponding photoelectric conversionelement 103. That is, the distance between the central axis C2 of thegreen color filter segment 115GS that corresponds to the normal pixelGb2 and the central axis P2 of the corresponding photoelectricconversion element 103 is the shift s2. In this example, the shift s2may be greater than the shift s5, but the present disclosure is notlimited thereto.

Furthermore, as shown in FIG. 1 and FIG. 3 , the green color filtersegment 115GS that corresponds to the normal pixel Gb8 has no shift withrespect to the corresponding photoelectric conversion element 103. Thatis, the central axis C8 of the green color filter segment 115GS thatcorresponds to the normal pixel Gb8 may overlap the central axis P8 ofthe corresponding photoelectric conversion element 103.

FIG. 4 is a partial cross-sectional view illustrating the solid-stateimage sensor 100 in accordance with some other embodiments of thepresent disclosure. For example, FIG. 4 may also be a partialcross-sectional view illustrating the solid-state image sensor 100 alongline A-A′ in FIG. 1 .

In some embodiments, the metal segment has a variable width with respectto the corresponding the grid segment 121S. For example, as shown inFIG. 4 , the width MW1 of the metal segment 111S1 (that is disposed onthe bottom of the grid segment 12151) may be greater than the width MW2of the metal segment 11152 (that is disposed on the bottom of the gridsegment 121S2), but the present disclosure is not limited thereto. Thewidth of the metal segment may be adjusted according to thecorresponding grid segment 121S.

FIG. 5 is a partial cross-sectional view illustrating the solid-stateimage sensor 100 in accordance with some other embodiments of thepresent disclosure. For example, FIG. 5 may also be a partialcross-sectional view illustrating the solid-state image sensor 100 alongline A-A′ in FIG. 1 .

In some embodiments, the condensing structure 119 has a variable widthwith respect to the corresponding color filter segment (e.g., the greencolor filter segment 115GS in FIG. 5 ). For example, as shown in FIG. 5, the width ML8 of the condensing structure 119-8 may be greater thanthe width ML2 of the condensing structure 119-2 and the width ML5 of thecondensing structure 119-5, but the present disclosure is not limitedthereto. The width of the condensing structure 119 may be adjustedaccording to the corresponding color filter segment (e.g., the greencolor filter segment 115GS in FIG. 5 ).

FIG. 6 is a partial top view illustrating the solid-state image sensor102 in accordance with some embodiments of the present disclosure. FIG.7 is a partial cross-sectional view illustrating the solid-state imagesensor 102 along line B-B′ in FIG. 6 . In more detail, FIG. 6 shows thepixel arrangement of the solid-state image sensor 102, and FIG. 7 showsa portion of the cross-sectional view of the solid-state image sensor102. It should be noted that some components of the solid-state imagesensor 102 have been omitted in FIG. 6 and FIG. 7 for sake of brevity.

Similarly, the color filter layer 115 has four color regions CR1, CR2,CR3, and CR4, and at least one of the auto-focus pixels is disposed inand corresponds to one of the four color regions CR1, CR2, CR3, and CR4.As shown in FIG. 6 , in some embodiments, the four color regions CR1,CR2, CR3, and CR4 form a unit pattern U2. As shown in FIG. 7 , the redcolor filter layer 115R is disposed above the photoelectric conversionelements 103, and the red color filter layer 115R has (or is dividedinto) red color filter segments 115RS.

As shown in FIG. 6 and FIG. 7 , the incident light L is from the leftside of the unit pattern U2 of the solid-state image sensor 102, and inthe color region CR2, the color filter layer 115 (the red color filtersegment 115RS) that corresponds to the normal pixel R2 is disposed onthe side that is closer to the incident light L, so that the colorfilter layer 115 (the red color filter segment 115RS) that correspondsto the normal pixel R2 may be referred to as the first color filtersegment, and the color filter layer 115 (the red color filter segment115RS) that corresponds to the normal pixel R5 or the normal pixel R8may be referred to as the second color filter segment. As shown in FIG.7 , in this embodiments, the width CD2 of the red color filter segment115RS that corresponds to the normal pixel R2 is greater than the widthCD5 (or CD8) of the red color filter segment 115RS that corresponds tothe normal pixel R5 (or R8).

FIG. 8 is a partial top view illustrating the solid-state image sensor104 in accordance with some other embodiments of the present disclosure.Referring to FIG. 8 , in some embodiments, more than one unit patternforms an array. That is, there is more than one unit pattern in thesolid-state image sensor 104. For example, as shown in FIG. 8 , thecolor filter layer (or the color regions) of the solid-state imagesensor 104 may form twenty-five (5×5) unit patterns, among which includethe unit pattern U1 as shown in FIG. 1 (in the left side of thesolid-state image sensor 104) and the unit pattern U2 as shown in FIG. 6(in the right side the solid-state image sensor 104), but the presentdisclosure is not limited thereto. The number and pixel arrangement ofunit patterns may be adjusted depending on actual need.

FIG. 9 is a partial top view illustrating the solid-state image sensor106 in accordance with some embodiments of the present disclosure. Asshown in FIG. 9 , in some embodiments, four color regions CR1, CR2, CR3,and CR4 of the solid-state image sensor 106 form a unit pattern U3. Forexample, each of the color regions CR1, CR2, CR3, and CR4 corresponds toa 3×3 pixel array. Moreover, the auto-focus pixel array PDAF is a 2×1pixel array, and is not disposed in the center of the unit pattern U3.

As shown in FIG. 9 , the incident light L is from the right side of theunit pattern U3 of the solid-state image sensor 106. In the color regionCR1, the color filter layer (or the (green) color filter segment) thatcorresponds to the normal pixel Gr5, Gr7, or Gr9 is disposed on the sidethat is closer to the incident light L, so that the width of the (green)color filter segment that corresponds to the normal pixel Gr5, Gr7, orGr9 is greater than the width of the (green) color filter segment thatcorresponds to the normal pixel Gr1, Gr2, Gr3, Gr4, or Gr6. In the colorregion CR2, the color filter layer (or the (red) color filter segment)that corresponds to the normal pixel R7, R8, or R9 is disposed on theside that is closer to the incident light L, so that the width of the(red) color filter segment that corresponds to the normal pixel R7, R8,or R9 is greater than the width of the (red) color filter segment thatcorresponds to the normal pixel R1, R3, R4, R5, or R6. In the colorregion CR3, the color filter layer (or the (blue) color filter segment)that corresponds to the normal pixel B7, B8, or B9 is disposed on theside that is closer to the incident light L, so that the width of the(blue) color filter segment that corresponds to the normal pixel B7, B8,or B9 is greater than the width of the (blue) color filter segment thatcorresponds to the normal pixel B1, B2, B3, B4, B5, or B6. In the colorregion CR4, the color filter layer (or the (green) color filter segment)that corresponds to the normal pixel Gb7, Gb8, or Gb9 is disposed on theside that is closer to the incident light L, so that the width of the(green) color filter segment that corresponds to the normal pixel Gb7,Gb8, or Gb9 is greater than the width of the (green) color filtersegment that corresponds to the normal pixel Gb1, Gb2, Gb3, Gb4, Gb5, orGb6.

FIG. 10 is a partial top view illustrating the solid-state image sensor108 in accordance with some embodiments of the present disclosure. Asshown in FIG. 10 , in some embodiments, four color regions CR1, CR2,CR3, and CR4 of the solid-state image sensor 108 form a unit pattern U4.For example, each of the color regions CR1, CR2, CR3, and CR4corresponds to a 3×3 pixel array. In some embodiments, the auto-focuspixels form two or more auto-focus pixel arrays PDAF. That is, there ismore than one auto-focus pixel array PDAF in the unit pattern U4. Forexample, two auto-focus pixel arrays PDAF are in the unit pattern U4. Inmore detail, two auto-focus pixel arrays PDAF are disposed in andcorrespond to the color regions CR3 and CR4. Moreover, each auto-focuspixel array PDAF is a 1×2 pixel array, and is disposed near the lowerside of the unit pattern U4.

As shown in FIG. 10 , the incident light L is from the right side of theunit pattern U4 of the solid-state image sensor 108. In the color regionCR1, the color filter layer (the (green) color filter segment) thatcorresponds to the normal pixel Gr7, Gr8, or Gr9 is disposed on the sidethat is closer to the incident light L, so that the width of the (green)color filter segment that corresponds to the normal pixel Gr7, Gr8, orGr9 is greater than the width of the (green) color filter segment thatcorresponds to the normal pixel Gr1, Gr2, Gr3, Gr4, Gr5, or Gr6. In thecolor region CR2, the color filter layer (the (red) color filtersegment) that corresponds to the normal pixel R7, R8, or R9 is disposedon the side that is closer to the incident light L, so that the width ofthe (red) color filter segment that corresponds to the normal pixel R7,R8, or R9 is greater than the width of the (red) color filter segmentthat corresponds to the normal pixel R1, R2, R3, R4, R5, or R6. In thecolor region CR3, the color filter layer (the (blue) color filtersegment) that corresponds to the normal pixel B5, B6, or B7 is disposedon the side that is closer to the incident light L, so that the width ofthe (blue) color filter segment that corresponds to the normal pixel B5,B6, or B7 is greater than the width of the (blue) color filter segmentthat corresponds to the normal pixel B1, B2, B3, or B4. In the colorregion CR4, the color filter layer (the (green) color filter segment)that corresponds to the normal pixel Gb7, Gb8, or Gb9 is disposed on theside that is closer to the incident light L, so that the width of the(green) color filter segment that corresponds to the normal pixel Gb7,Gb8, or Gb9 is greater than the width of the (green) color filtersegment that corresponds to the normal pixel Gb1, Gb4, Gb5, or Gb6.

FIG. 11 is a partial top view illustrating the solid-state image sensor110 in accordance with some embodiments of the present disclosure. Asshown in FIG. 11 , in some embodiments, four color regions CR1, CR2,CR3, and CR4 of the solid-state image sensor 110 form a unit pattern U5.For example, each of the color regions CR1, CR2, CR3, and CR4corresponds to a 4×4 pixel array. In some embodiments, the auto-focuspixels form two or more auto-focus pixel arrays PDAF. That is, there ismore than one auto-focus pixel array PDAF in the unit pattern U5. Forexample, two auto-focus pixel arrays PDAF are in the unit pattern U5. Inmore detail, two auto-focus pixel arrays PDAF are disposed in andcorrespond to all color regions (i.e., the color regions CR1, CR2, CR3,and CR4). Moreover, each auto-focus pixel array PDAF is a 2×2 pixelarray.

As shown in FIG. 11 , the incident light L is from the right side of theunit pattern U5 of the solid-state image sensor 110. In the color regionCR1, the color filter layer (the (green) color filter segment) thatcorresponds to the normal pixel Gr11, Gr12, Gr13, or Gr14 is disposed onthe side that is closer to the incident light L, so that the width ofthe (green) color filter segment that corresponds to the normal pixelGr11, Gr12, Gr13, or Gr14 is greater than the width of the (green) colorfilter segment that corresponds to the normal pixel Gr1, Gr2, Gr3, Gr4,Gr5, Gr6, Gr7, Gr8, Gr9, or Gr10. In the color region CR2, the colorfilter layer (the (red) color filter segment) that corresponds to thenormal pixel R13, R14, R15, or R16 is disposed on the side that iscloser to the incident light L, so that the width of the (red) colorfilter segment that corresponds to the normal pixel R13, R14, R15, orR16 is greater than the width of the (red) color filter segment thatcorresponds to the normal pixel R1, R2, R5, R6, R7, R8, R9, R10, R11 orR12. In the color region CR3, the color filter layer (the (blue) colorfilter segment) that corresponds to the normal pixel B9, B10, B15 or B16is disposed on the side that is closer to the incident light L, so thatthe width of the (blue) color filter segment that corresponds to thenormal pixel B9, B10, B15 or B16 is greater than the width of the (blue)color filter segment that corresponds to the normal pixel B1, B2, B3,B4, B5, B6, B7, B8, B11, or B12. In the color region CR4, the colorfilter layer (the (green) color filter segment) that corresponds to thenormal pixel Gb13, Gb14, Gb15, or Gb16 is disposed on the side that iscloser to the incident light L, so that the width of the (green) colorfilter segment that corresponds to the normal pixel Gb13, Gb14, Gb15, orGb16 is greater than the width of the (green) color filter segment thatcorresponds to the normal pixel Gb3, Gb4, Gb5, Gb6, Gb7, Gb8, Gb9, Gb10,Gb11, or Gb12.

FIG. 12 is a partial top view illustrating the solid-state image sensor112 in accordance with some embodiments of the present disclosure. Asshown in FIG. 12 , in some embodiments, four color regions CR1, CR2,CR3, and CR4 of the solid-state image sensor 112 form a unit pattern U6.For example, each of the color regions CR1, CR2, CR3, and CR4corresponds to a 4×4 pixel array. In some embodiments, the auto-focuspixels form two or more auto-focus pixel arrays PDAF. That is, there ismore than one auto-focus pixel array PDAF in the unit pattern U6. Forexample, eight auto-focus pixel arrays PDAF are in the unit pattern U6.In more detail, eight auto-focus pixel arrays PDAF are disposed in andcorrespond to all color regions (i.e., the color regions CR1, CR2, CR3,and CR4). Moreover, each auto-focus pixel array PDAF is a 2×1 pixelarray.

As shown in FIG. 12 , the incident light L is from the right side of theunit pattern U6 of the solid-state image sensor 112. In the color regionCR1, the color filter layer (the (green) color filter segment) thatcorresponds to the normal pixel Gr13, Gr14, Gr15, or Gr16 is disposed onthe side that is closer to the incident light L, so that the width ofthe (green) color filter segment that corresponds to the normal pixelGr13, Gr14, Gr15, or Gr16 is greater than the width of the (green) colorfilter segment that corresponds to the normal pixel Gr1, Gr2, Gr3, Gr4,Gr5, Gr8, Gr9, or Gr12. In the color region CR2, the color filter layer(the (red) color filter segment) that corresponds to the normal pixelR13, R14, R15, or R16 is disposed on the side that is closer to theincident light L, so that the width of the (red) color filter segmentthat corresponds to the normal pixel R13, R14, R15, or R16 is greaterthan the width of the (red) color filter segment that corresponds to thenormal pixel R1, R2, R3, R4, R5, R8, R9, or R12. In the color regionCR3, the color filter layer (the (blue) color filter segment) thatcorresponds to the normal pixel B13, B14, B15 or B16 is disposed on theside that is closer to the incident light L, so that the width of the(blue) color filter segment that corresponds to the normal pixel B13,B14, B15 or B16 is greater than the width of the (blue) color filtersegment that corresponds to the normal pixel B1, B2, B3, B4, B5, B8, B9,or B12. In the color region CR4, the color filter layer (the (green)color filter segment) that corresponds to the normal pixel Gb13, Gb14,Gb15, or Gb16 is disposed on the side that is closer to the incidentlight L, so that the width of the (green) color filter segment thatcorresponds to the normal pixel Gb13, Gb14, Gb15, or Gb16 is greaterthan the width of the (green) color filter segment that corresponds tothe normal pixel Gb1, Gb2, Gb3, Gb4, Gb5, Gb8, Gb9, or Gb12.

In summary, according to the embodiments of the present disclosure, thesolid-state image sensor includes color filter segments having variablewidths, which may improve channel separation, thereby improving thequality of the image signal from the photoelectric conversion elementsof the solid-state image sensors.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure. Therefore, the scope of protection should bedetermined through the claims. In addition, although some embodiments ofthe present disclosure are disclosed above, they are not intended tolimit the scope of the present disclosure.

Reference throughout this specification to features, advantages, orsimilar language does not imply that all of the features and advantagesthat may be realized with the present disclosure should be or are in anysingle embodiment of the disclosure. Rather, language referring to thefeatures and advantages is understood to mean that a specific feature,advantage, or characteristic described in connection with an embodimentis included in at least one embodiment of the present disclosure. Thus,discussions of the features and advantages, and similar language,throughout this specification may, but do not necessarily, refer to thesame embodiment.

Furthermore, the described features, advantages, and characteristics ofthe disclosure may be combined in any suitable manner in one or moreembodiments. One skilled in the relevant art will recognize, in light ofthe description herein, that the disclosure can be practiced without oneor more of the specific features or advantages of a particularembodiment. In other instances, additional features and advantages maybe recognized in certain embodiments that may not be present in allembodiments of the disclosure.

What is claimed is:
 1. A solid-state image sensor, comprising:photoelectric conversion elements; a color filter layer disposed abovethe photoelectric conversion elements; wherein the photoelectricconversion elements and the color filter layer form normal pixels andauto-focus pixels, the color filter layer that correspond to the normalpixels are divided into first color filter segments and second colorfilter segments, the first color filter segments are disposed on atleast one side that is closer to an incident light, and a width of thefirst color filter segments is greater than a width of the second colorfilter segments.
 2. The solid-state image sensor as claimed in claim 1,wherein at least one of the first color filter segments that is adjacentto the auto-focus pixels has a greater width than other of the firstcolor filter segments.
 3. The solid-state image sensor as claimed inclaim 1, wherein the color filter layer has four color regionscorresponding to at least two different colors, and at least one of theauto-focus pixels is disposed in and corresponds to one of the fourcolor regions.
 4. The solid-state image sensor as claimed in claim 3,wherein the width of the first color filter segments in one of the fourcolor regions is different from the width of the first color filtersegments in another of the four color regions.
 5. The solid-state imagesensor as claimed in claim 3, wherein each of the four color regionscorresponds to an n² pixel array, and n is an integer greater than orequal to
 3. 6. The solid-state image sensor as claimed in claim 5,wherein the auto-focus pixels form an auto-focus pixel array, and theauto-focus pixel array is a p×q pixel array, where p and q are integersless than n.
 7. The solid-state image sensor as claimed in claim 3,wherein the four color regions form a unit pattern, and more than oneunit pattern forms an array.
 8. The solid-state image sensor as claimedin claim 3, wherein the auto-focus pixels are disposed in and correspondto all of the four color regions.
 9. The solid-state image sensor asclaimed in claim 3, wherein the auto-focus pixels are disposed in andcorrespond to at least two of the four color regions.
 10. Thesolid-state image sensor as claimed in claim 1, wherein the normalpixels have a constant pixel width that is equal to or less than 0.7 μm.11. The solid-state image sensor as claimed in claim 1, furthercomprising: a grid structure disposed between the first color filtersegments and between the second color filter segments, wherein the gridstructure has grid segments, and each of the grid segments has avariable width.
 12. The solid-state image sensor as claimed in claim 11,further comprising: a metal grid disposed on a bottom of the gridstructure, wherein the metal grid has metal segments, and the metalsegments have a constant width.
 13. The solid-state image sensor asclaimed in claim 11, further comprising: a metal grid disposed on abottom of the grid structure, wherein the metal grid has metal segments,and each of the metal segments has a variable width with respect to acorresponding one of the grid segments.
 14. The solid-state image sensoras claimed in claim 1, further comprising: condensing structuresdisposed on and corresponding to the first color filter segments and thesecond color filter segments.
 15. The solid-state image sensor asclaimed in claim 14, wherein each of the condensing structures has avariable width with respect to a corresponding one of the first colorfilter segments and the second color filter segments.
 16. Thesolid-state image sensor as claimed in claim 1, wherein at least one ofthe first color filter segments and the second color filter segments hasa shift with respect to a corresponding one of the photoelectricconversion elements.
 17. The solid-state image sensor as claimed inclaim 1, wherein the auto-focus pixels form two or more auto-focus pixelarrays.
 18. The solid-state image sensor as claimed in claim 17, whereinthe auto-focus pixel arrays are disposed in and correspond to at leasttwo of the four color regions.
 19. The solid-state image sensor asclaimed in claim 17, wherein the auto-focus pixel arrays are disposed inand correspond to all of the four color regions.
 20. The solid-stateimage sensor as claimed in claim 1, wherein the normal pixels comprisered color filters, green color filters, blue color filters, yellow colorfilters, white color filters, cyan color filters, magenta color filters,or IR/NIR color filters.